Twitching and tingling are generally due to peripheral neuropathies or vascular pathologies. Hence peripheral vascular pathologies have to be ruled out either by angiograms or by dopplar studies. Nerve conduction studies should be done. Vitamin B12 deficiency too should be looked into. There are many other causes of nerve disorder causing these paresthesia or abnormal sensations including diabetes, hypothyroidism, chronic involvement of liver or kidney, chronic alcohol use etc. Hypoparathyroidism too should be looked into apart from hypothyroidism. Neck strain, spondylotic changes in cervical vertebrae, bone disease or bad posture should be looked into. Nerve infections as in lyme’s disease too should be investigated. Multiple sclerosis and G B Syndrome (less likely) are two other possibilities.
I would suggest you get the blood levels of the following checked if they have not already been checked: potassium, calcium, sodium, magnesium, vitamin B complex, or vitamins B1, B3, or B6 and Vitamin D. Generally deficiencies of any of the above can cause muscle twitching and spasms in localized or generalized areas of the body. Get your kidney function, parathyroid gland function and adrenal function tests done because these affect the electrolyte balance in the body. Stress, alcohol, caffeine and fatigue all cause similar symptoms. Hence if you take alcohol or coffee then cut this down. Sleep at regular hours and see if it helps. Certain sleep disorders and peripheral nerve disorders due to diabetes or hypothyroidism can also be the cause.
Do discuss this with your doctor and get yourself examined. Take care!
I felt like I had to weigh in on this, as I read the doctor`s response to your question, and quite frankly, found it excessively long and fairly unhelpful.She basically goes over every condition known to man (or woman) that could ever afflict a person, which really doesn`t provide you with any guidance.
Here are my thoughts, for what they`re worth (and I`m no doctor) - twitching on its own is NEVER a problem. The most it will be is a minor annoyance. Some people are just twitchers, for whatever reason, whether it be anxiety, a vitamin deficiency (as the doctor did mention), a thyroid issue, or any other of a plethora of completely benign issues. I myself twitch all the time, and all over. The only time twitching becomes a worry is if it is accompanied by actual clinical weakness and muscle atrophy. It does not sound to me like these things are happening to you.
Best of luck!